The company, which also makes pharmaceuticals and specialty chemicals, said that it now expects 2021 adjusted earnings before interest, tax, depreciation and amortization of 5.4-5.8 billion euros, and revenues of 18.5-19.5 billion.
It had earlier guided for core earnings to grow organically by a high single-digit to low teens percentage figure and strong organic revenue growth.
In the first quarter, EBITDA reached 1.51 billion euros, while revenues came in at 4.63 billion.
Merck is expected to publish first-quarter 2021 figures as scheduled on May 12.
(Reporting by Arno Schuetze; Editing by Chizu Nomiyama)